Three-dimensional structure of transmembrane domain 6 of natural resistance associated macrophage protein 2 in hexafluoroisopropanol aqueous solution

Abstract

Natural resistance associated macrophage protein 2 plays an important role in adsorption of a broad range of divalent metal ions, including iron, cobalt, zinc, copper, nickel, manganese, cadmium and lead. The protein contains 12 putative transmembrane domains, two highly conserved and mutation sensitive histidines were found in the predicted transmembrane domain 6, mutation of two histidines at either or both sites causing deficiency of function. In this paper, the structure of the peptide from transmembrane 6 of natural resistance associated macrophage protein 2 was investigated in 60% hexafluoroisopropanol aqueous solution by circular dichroism and nuclear magnetic resonance spectroscopy. Our study demonstrated the peptide forms a discontinuous α helix structure with two helices spanning over Ala256-Ile259 and Asn268-Ser278.